1. Field of the Invention
This invention relates to a majority decision logic circuit employing transistors of the Metal-Oxide-Semiconductor construction, i.e. MOS transistors.
2. Description of the Prior Art
Heretofore, several kinds of circuits have been proposed for deciding the majority of the count values of a plurality of counter circuits. These conventional circuits employ, for example, a method of addition of currents utilizing resistors or magnetic fluxes by magnetic cores. They are all simple in circuit construction, but are not suitable for fabrication as integrated circuits.
Also, there has been proposed a majority decision logic circuit employing transistors and diodes, which circuit is suitable for fabrication as an integrated circuit. This circuit comprises three 2-input AND gates and one 3-input OR gate, for example, in the case of deciding the majority of three signals, and is designed to provide an output signal "1" when input signals "1" have been applied to two of the three inputs or to all of them, and to provide an output signal "0" when an input signal "1" has been applied to any one or none of the three inputs.
But since the AND gate or OR gate such as mentioned above is composed of many electronic parts, the abovesaid majority decision logic circuit has the defect of complicated circuit construction in addition to the necessity of a large number of parts, even for the majority decision of only three input signals. The circuit for the majority decision of only three input signals has such defects, and there has not been realized a circuit which has an odd number of logic circuits and is capable of deciding the majority of output signals of the logic circuits or individually picking up the outputs from the logic circuits.